Art of making enamel ware



Patented Oct. 21, 1930 I i 7 1,779,273

UNITED. STATES PATENT OFFICE OSCAR HOMMEL, F PITTSBURGH, PENNSYLVANIA ART OF MAKING ENAMEL WARE No Drawing. Application filed April 26, 1928. Serial N 0. 273,157.

My invention relates to improvements in narily completed with two or more applicathe art of coating metallic atricles, and spetions of enamel and with firings following cifically articles of iron and steel, with a the two repeated applications. It has hither fused and vitreousenamel. to been known that if in the first of the slips In the practice of my invention, and bein which the article is dipped such metallic 55 ginning with the properly prepared article oxides as-I have indicated be present, the of ferrous metal, ordinarily of iron or steelenamel coating is more securely united upon a steel wash basin, for example,-I see to it the steel surface. I have found that, proceedthat the surface is by known means freed of ing in the .manner described, I obtain still substances accidentally presentthe grease better adhesion of the coating to the steel, 00 for example which may remain, consequent and I have found that, whilea second coating upon a pressing or spinning operation-and step may be taken, it no longer is essential to otherwise cleaned. I then cause a film of oxa successful job, and that by one application ide of another metal of the iron group, ofv of enamel to the oxide filmed steel a good cobalt, nickel, manganese, or a film of comand serviceable enameling may be accom- 65 bined oxides of such other metals, or of any plished. two of them to form upon the surface of the A known alternative method of applying article. The film may be formed in a vari the enamel is by sifting the finely ground ety of ways. For example, the article may enameling substance, essentially glass, upon be heated to red heat and while at that temthe article when heated to 1800 F. or ther 70 perature a solution of a salt of the desired abouts. If the article he prepared with the metal may be sprayed upon it,an aqueous film coating of metallic oxide, as I have desolution, for example, of carbonate of cobalt, scribed, the adhesion of the enamel coating or of the nitrate. The heat to which the applied by sifting will be found to be greatsprayed on material is thus subjected has two ly improved. 75

effects: the driving ofi of the solvent and the I claim as my invention: reduction of the salt from the more complex 1, In the anufacture of namel Ware havcarbonate or nitrate to the oxide, and the ing a body of metal and a surface coating oxide so produced together with inevitably of vitreous nature the procedure herein deformed ()Xide f i II f rmS a ating or film scribed which consists in coating the surface 8 upon the surface of the article. of a body of a ferrous metal with a film of Alternatively, instead of spraying the sooxide of another metal selected from a group lution upon the article when heated, the arconsisting of cobalt, nickel, and manganese, ticle may be immersed in the solution, and forming the enamel coating upon the preferably a saturated solution. Being resurface so prepared. moved from such immersion the articleis 2. In the manufacture of enamel ware havcoated with the solution and, after drying, it ing a body of metal and a surface coating of continues to be coated with the precipitated vitreous nature, the procedure herein desalt in the form an inclustationh cribed which consists in coating the surface 40 coated article then is' heated, and as a temf a b dy f ir or t l ith a fil f tal. perature of from 1000 to 1400 F. is plic oxide including the oxide of cobalt, and preached the reduction of the salt Will 000111 fQrnfi g the enamel coating upon the 5111a and the film of oxide will form, with subface so prepared. stantially the same result as in the procedure T 3, In the manufacture of enamel ware hav- 5 first described. inga body of metal and a surface coating-of.

To the surface coated with such film of vitreous naturp the procedure herein de-- oxide, the enamel is applied, and vitrified in scribed which onsists in boating the surface usual manner. For instance, the article may of a body of a errous metal with a film of be dipped in a slip of enamel, dried, and fired. metallic oxide from inorganic compounds se- 50 The enamel coating of such ware is ordilected from a group of metals consisting of cobalt, nickel, and manganese, and forming upon the film-covered surface a coatmg of enamel.

4. In the manufacture of enamel ware the my hand.

OSCAR HOMMEL. 

